Zinc Sulfide Films Research Articles

Insights into the flotation performance of ethylenediamine surface modified hemimorphite: Experimental and DFT study

Upon utilizing micro-flotation, contact angle, AFM, ToF-SIMS, XPS, ICP-OES, and DFT calculations, the influence of ethylenediamine (EDA) on the flotation mechanism of hemimorphite was investigated. The addition of EDA to the flotation system led to a 25.15 % increase in flotation recovery efficiency. Contact angle and AFM analysis indicated that EDA enhanced both the hydrophobicity and surface roughness of hemimorphite. Subsequently, ToF-SIMS deep profiling analysis indicated that EDA modification facilitated the incorporation of sulfur ions into the internal structure of hemimorphite, forming a uniform zinc sulfide film. Furthermore, XPS and ICP-OES analysis demonstrates an increase in sulfides on the surface of the hemimorphite after EDA modification. Additionally, the results of DFT calculations showed that the adsorption energy of an EDA molecule on the hemimorphite (1 1 0) surface was −956.492 kJ/mol.

Physical Properties of Nanostructured Zinc Sulfide Thin Films Deposited by the PLD Method for Gas Sensing

The pulsed laser deposition (PLD) technique created nanostructured semiconducting zinc sulfide (ZnS) thin films onto a quartz substrate. A gas sensing static unit, field emission scanning electron microscopy (FE-SEM), and X-ray diffraction (XRD) were used to analyze the structural, surface morphology, and gas sensing properties of the as-deposited thin films. After the ZnS thin films were formed, they were heated to evaluate the effects of annealing on the characteristics of the ZnS film. XRD analysis reveals that the ZnS thin films exhibit a structure similar to zinc blend cubes, with a preference for the (111) orientation. The X-ray diffraction (XRD) patterns that emerge during annealing show that ZnS thin films become more crystalline. Grain size increases as the annealing temperature rises. Images captured by field emission scanning electron microscopy (FESEM) revealed a grain-like sphere for each of the annealed thin films, confirming the growth of grains. The UV-Vis spectra showed that the ZnS samples' transmittance boosts after annealing because their crystalline quality is improved. The transmittance is measured within the 400 ̶ 900 nm band, and the optical band gap is direct at 3.72 eV, decreasing to 3.51 eV at 350 °C during annealing. Annealing significantly improves the physical properties of ZnS thin films, according to all presented data. NO2 and CO2 gas were used to obtain the I-V values ​​of the samples. The ability of ZnS thin films formed at different annealing temperatures was tested using NO2 gas. The sensors were fabricated and tested at different operating temperatures and NO2 gas concentrations of 100, 300, 400, 500, and 700 ppm.

Influence of concentration on optical and structural properties of zinc sulfide films using spray pyrolysis technique

Influence of concentration on optical and structural properties of zinc sulfide films using spray pyrolysis technique

Fabrication of cobalt-doped ZnS thin films by successive ionic layer adsorption and reaction for UV–visible photodetectors on flexible substrate

Photodetectors are widely employed in research and innovation, necessitating swift response times, precision, and stability. However, their application in commercial and industrial settings is hindered by limited flexibility and a constrained capacity to respond across a broad spectrum. In this study, we adopted a facile, cost-effective, and room temperature Successive Ionic Layer Adsorption and Reaction (SILAR) technique to craft thin films of Cobalt-doped ZnS on a flexible paper substrate. The Cobalt doping, with varying wt.% (0, 0.5, 1, and 1.5) exhibiting excellent responsivity to both UV and visible spectra. Zinc Sulfide (ZnS), renowned for its wide bandgap, serves as a versatile semiconductor, making it an ideal candidate for photodetectors. The introduction of Cobalt broadened the responsivity of ZnS, covering a wide spectrum, including UV and visible regions. Structural confirmation of the material was achieved through XRD and Raman analyses. Scanning Electron Microscopy revealed the aggregated spherical nanostructure of ZnS on the cellulose substrate. Verification of Cobalt presence in the ZnS thin film and assessment of elemental oxidation states were conducted using XPS. Temporal response and I–V characteristics of the device were evaluated under varying light conditions, specifically at wavelengths of 325 nm and 700 nm at different intensities. Responsivity calculations yielded values of 22.5 mA/W for UV illumination (light intensity 0.6 mW/cm2) and 37.6 mA/W (light intensity 0.4 mW/cm2) for visible light, with corresponding response times recorded as 1.45 s and 2.13 s, respectively. In addition to performance assessments, bending cycle studies were conducted, demonstrating the excellent flexibility of the device up to 800 cycles. The Cobalt-doped ZnS device, as fabricated, emerges as a promising material for energy harvesting.

A Comparative Study of the Structural and Optical Properties of ZnS Films Deposited by Spray‐Pyrolysis Technique

AbstractThis study aims at synthesizing zinc sulfide (ZnS) thin films using spray pyrolysis method. The effect of the Zn concentration on the physical properties of ZnS is investigated using X‐ray diffraction (XRD), scanning electron microscope (SEM), UV–Vis spectrophotometer, photoluminescence (PL), and Raman spectroscopy. XRD shows a preferential orientation along the (111) direction corresponding to the ZnS cubic structure. Based on the XRD results, it is seen that low zinc concentrations compared to sulfur content can increase the crystalline quality of films. Raman spectra confirm the presence of the ZnS cubic structure observed by XRD and show the presence of sprayed ZnS vibrational modes for all films. PL emission spectrum of ZnS confirms the presence of Zn and S atoms at all molar concentrations. SEM reveals densely packed and uniformly distributed grains with precise shapes. The elemental analysis confirms the growth of stochiometric Zn/S ratio. The optical analysis shows a high transmittance around 88% in the visible range of the solar spectrum with optical band gaps varying from 3.4 to 3.6 eV. These properties are interesting and show that ZnS thin films can be used as buffer layers in thin film solar cells applications.

Influence of magnesium dopant on ZnS thin films by low-cost chemical bath deposition technique

The Magnesium (Mg) doped Zinc Sulphide (ZnS) thin films were synthesized by the low-cost chemical bath deposition (CBD) technique. The ZnS films were deposited for different doping concentrations of magnesium (Mg). XRD patterns of the films showed a cubic phase with a preferred (111) plane orientation. The crystallinity of the films was varied with magnesium doping. The bandgap of the film was decreased from 3.76 eV to 3.37 eV with magnesium. The photoluminescence of the undoped and doped ZnS films was investigated. The electrical properties of the films were changed significantly with magnesium doping.

Multilayer Smart Holographic Label with Integrated RFID for Product Security and Monitoring

Counterfeiting presents a major economic problem and an important risk for the public health and safety of individuals and countries. To make the counterfeiting process more difficult, and to ensure efficient authentication, a solution would be to attach anti-counterfeit labels that include a radio frequency identification (RFID) element to the products. This can allow real-time quality check along the entire supply chain. In this paper we present the technology optimized to obtain a multilayer holographic label with a high degree of security, patterned on a thin zinc sulfide film of a semi-transparent holographic foil rather than on the standard substrate for diffractive optical elements (metallized foil). The label is applied onto the product surface or packaging for anti-counterfeit protection. The developed multilayer structure contains various elements such as: a holographic background, nanotext-type elements, holographic elements, and an RFID antenna. The employed semi-transparent holographic foil offers the RFID antenna the possibility to transmit the electromagnetic signal through the label and thus to maximize the antenna footprint, achieving up to 10 m reading distance, with a 6 cm × 6 cm label, much smaller than the commercial standard (minimum 10 cm × 10 cm).

Effect of Chemical Bath Deposition Variables on the Properties of Zinc Sulfide Thin Films: A Review.

Zinc sulfide (ZnS) thin films prepared using the chemical bath deposition (CBD) method have demonstrated great viability in various uses, encompassing photonics, field emission devices, field emitters, sensors, electroluminescence devices, optoelectronic devices, and are crucial as buffer layers of solar cells. These semiconducting thin films for industrial and research applications are popular among researchers. CBD appears attractive due to its simplicity, cost-effectiveness, low energy consumption, low-temperature compatibility, and superior uniformity for large-area deposition. However, numerous parameters influence the CBD mechanism and the quality of the thin films. This study offers a comprehensive review of the impact of various parameters that can affect different properties of ZnS films grown on CBD. This paper provides an extensive review of the film growth and structural and optical properties of ZnS thin films influenced by various parameters, which include complexing agents, the concentration ratio of the reactants, stirring speed, humidity, deposition temperature, deposition time, pH value, precursor types, and annealing temperature environments. Various studies screened the key influences on the CBD parameters concerning the quality of the resulting films. This work will motivate researchers to provide additional insight into the preparation of ZnS thin films using CBD to optimize this deposition method to its fullest potential.

Synthesis of Zinc Sulfide Nanocrystals by Chemical Bath Deposition Methods

Chemical bath deposition method was used to create zinc sulfide (ZnS) nanoparticles. The CBD contained fixed components such as ZnCl2, NH4NO3, and CS (NH2)2 and KOH. Samples were heated at 90°C in a bath with magnetic agitation. Homogeneity, high transparency, adhesion, and crystalline ZnS films were achieved using KOH (1.4 M). For structural and optical investigation, the produced nanoparticles are examined using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR) Spectroscopy, and ultraviolet-visible (UV-Vis) Absorption Spectroscopy. In XRD, the cubic crystal structure can be seen at 350nm, the UV-Vis spectrum reveals a blue peak. The absorbance and type of bonds present in samples are determined by FTIR spectra.

Chemical Synthesis, Morphology, and Optical Properties of Manganese-Doped Zinc Sulfide Films

Chemical Synthesis, Morphology, and Optical Properties of Manganese-Doped Zinc Sulfide Films

Study the optical parameters of aluminum doped ZnS films deposited on soda-lime glass substrate

Zinc Sulfide (ZnS) thin films have gained popularity due to their potential field applications. ZnS doped with various elements is redefining academic and industrial research. Pulsed laser deposition (PLD) was applied in the deposition process of undoped ZnS and aluminum (Al) doped zinc sulfide (AZS) on cleaned soda lime glass substrates. The doping effects of aluminum concentration (0, 2, 4, and 6%) on the characteristics of ZnS films were investigated. The ZnS and AZS thin films exhibited a direct allowed bandgap in the range of 3.40 to 3.56 eV, The band gap has been observed to be higher (3.56 eV) indicating blue shift. The linear optical parameters such as oscillator energy (E0), dispersion energy (Ed), and static refractive index (n0) were calculated using Wemple and DiDominco's model to find the nonlinear optical susceptibility χ 3 and nonlinear refractive index n2. The increasing nonlinear parameters χ 3 and n2 suggest nonlinear optical applications for AZS. The experimental methods and results are described, and the results are compared to published data.

Preparation of ZnS-decorated MWCNTs/p-Si hybrid photodetector by pulsed laser deposition

In the present work, a zinc sulfide (ZnS) nanostructure film is deposited on multi-walled carbon nanotubes (MWCNTs) by means of pulsed laser deposition technique. The structural, morphological, and optical properties of ZnS-decorated MWCNTs are investigated. X-ray diffraction (XRD) studies showed the presence of peaks related to polycrystalline faced-center cubic ZnS and MWCNTs. The best crystallinity is found for ZnS/MWCNTs nanocomposite prepared at 5.3 J/cm2. Scanning electron microscope (SEM) investigation shows that the deposited ZnS films have a smooth structure with some spherical particles attached to the film surface. The SEM image of the ZnS-decorated MWCNTs confirms the formation of a nanocomposite morphology structure. The optical energy gap of ZnS film decreases from 4 to 3.85 eV as laser fluence increases from 5.3 to 6.5 J/cm2, and in addition, the energy gap of ZnS-decorated MWCNTs nanocomposite film is smaller than that of ZnS film. The current-voltage characteristics of ZnS/Si and ZnS-decorated MWCNTs/Si heterojunction photodetectors are measured in dark and illumination conditions. The responsivity of n-ZnS/p-Si and n-ZnS/MWCNTs/p-Si prepared at 6.5 J/cm2 was found to be as high as 0.35 at 710 nm and 0.674 A/W at 610 nm, respectively. The figures of merit of the ZnS/Si photodetectors, including external quantum efficiency and specific detectivity, were improved after being embedded with MWCNTs. The band lineup of n-ZnS-decorated MWCNTs/p-Si under illumination was constructed.

The fabrication and characterization of thermal evaporated n-ZnS/p-Si heterojunction and ZnS-Au Schottky photodiodes

The wide bandgap of zinc sulfide (ZnS) is optimum for the detection of UV wavelengths. In the research work presented here, thermal evaporated ZnS layer is paired with Si and Au to form heterojunction and Schottky photodiodes. The devices showed UV detection capabilities. The barrier height of the n-ZnS/p-Si heterojunction varied from 0.06 to 0.1 eV when the ambient temperature was increased up to 420 K. The series resistance and ideality factors varied from 20 to 130 kΩ and 2–3 respectively. The built-in potential was about 0.76 V. The heterojunction showed a responsivity of 0.08 A/W and quantum efficiency of 0.3. The Au/ZnS Schottky junction was found to have an ideality factor of 2.53 with a barrier height of 0.46 eV. The response times of both the devices were found to be almost similar but it was much faster than that of the isolated ZnS film. This is due to the faster movement of photogenerated charges in the electric field of the junction.

Selective thermal emission and infrared camouflage based on layered media

Infrared camouflage based on artificial thermal metasurfaces has recently attracted significant attention. By eliminating thermal radiation differences between the object and the background, it is possible to hide a given object from infrared detection. Infrared camouflage is an important element that increases the survivability of aircraft and missiles, by reducing target susceptibility to infrared guided threats. Herein, a simple and practicable design is theoretically presented based on a multilayer film for infrared stealth, with distinctive advantages of scalability, flexible fabrication, and structural simplicity. The multilayer medium consists of silicon substrate, carbon layer and zinc sulfide film, the optical properties of which are determined by transfer matrix method. By locally changing the thickness of the coating film, the spatial tunability and continuity in thermal emission are demonstrated. A continuous change of emissive power is further obtained and consequently implemented to achieve thermal camouflage functionality. In addition, other functionalities, like thermal illusion and thermal coding, are demonstrated by thickness-engineered multilayer films.

Zinc sulfide based thin film photodetector prepared by spray pyrolysis

The chemical spray pyrolysis technique was used to synthesis zinc sulfide (ZnS) thin films without annealing treatment. The thin films were grown on a glass substrate under various Zn:S ratios (1:1,1:2, 1:3). The spray solution was prepared by combining zinc acetate dihydrate and thiourea as precursor materials for Zn2+ and S2- ions, with deionized water serving as the solvent. The results of the ZnS film on glass showed a well-characterized thin film acquired using Zn:S of (1:1,1:2,1:3) molar ratio, nozzle to substrate distance (NSD) of 30 cm and a substrate temperature of 300 °C. Strong peaks (111) were obtained for all samples via X-ray diffraction analysis. The photoluminescence spectrum showed three distinctive peaks at roughly 2.36, 2.98, and 3.6 eV and the energy gap of the synthesized thin film was 3.66 eV. The MSM photodetectors (PDs) made from the layers on glass substrate showed response to UV illumination (400 nm), exhibiting a photosensitivity of 665% at base voltage of 3 V.

Fabrication of ZnS layer on silicon nanopillars surface for photoresistor application

It is the first time that the Zinc sulfide (ZnS) film is deposited on silicon (Si) planar and nanopillars surface for photoresistor application. The 200 nm thick ZnS layer is deposited by RF magnetron sputtering, and it can cover the planar and nanopillar Si surface tightly. Both the ZnS film on planar and nanopillar Si surfaces are well crystallinity from the XRD patterns. Compared with the ZnS film on the planar Si surface, the ZnS/ Si nanopillars structure has a lower reflection, and the response of the ZnS film on Si nanopillars is much higher than that on planar Si surface.

Comprehensive analysis of microstructural, optical and electrical properties of ZnS thin films deposited by cost effective SILAR technique

Cost effective SILAR technique was utilized to synthesis uniform ZnS thin films by varying solution molarity. The structural, composition, optical, and transport properties of zinc sulphide films synthesized were explored in detail. The properties of the films with different thickness were studied using, XRD, SEM-EDS, UV–visible spectroscopy, and I-V probe station. XRD analysis revealed the cubic structure of as prepared and heat treated ZnS films. The films comprised of moderate sized crystallites(15 nm). The films were well adherent and EDS analysis confirmed the marginal stoichiometry of the films. Significant optical absorption was seen in the near UV region. The films showed high absorption coefficient values (106 cm−1). The optical band gap of the as prepared and heat-treated films was found to be in the range 3.1 eV to 3.6 eV. The penetration depth showed the cut off wavelength in UV region. The electrical properties were studied using silver ohmic contacts. The resistivity of the films was in the range 102 Ω cm, and the carrier concentration was observed to be of the order of and 1014 cm3. The sufficiently thick ZnS thin films with high absorption coefficient can be used for UV photodetector applications.

Deposition of zinc sulphide films from thiourea complexes and a study of their optical properties

Deposition of zinc sulphide films from thiourea complexes and a study of their optical properties

Effects of deposition time on structural and optical properties of ZnS and ZnS/Au thin films grown by thermal evaporation

In this work, by exploiting the thermal evaporation technique, Zinc sulfide (ZnS) thin films are grown on glass substrates at 473 K. The effects of the deposition time on the thickness, structural, morphological, and optical properties of the thin films are investigated. The samples were deposited at 4 × 10−6 mbar with different deposition times (10, 20, and 30 min) whereas the thin films are characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), and ultraviolet–visible spectrophotometers (UV–Vis). XRD analysis indicates that all fabricated films have a cubic structure of β-ZnS phase. Moreover, crystallite size, lattice constant, dislocation density, and micro-strain are calculated from XRD data. According to the results, crystallite size shows an increasing trend from 7.05 to 12.28 nm as deposition time increases. The dependency of surface roughness on deposition time is also observed. Optical parameters of the films such as transmittance spectra, direct optical band gap energy, refractive index, extinction coefficient, complex dielectric constant, dispersion energy parameters, static refractive index, and static high-frequency dielectric constant are carefully determined. The films exhibit high transparency and zero absorption in the visible and infrared regions. The refractive index values can be well fitted to Cauchy's relations for extrapolation to near strong absorption region. The prepared ZnS thin film with low surface roughness, high transparency, and large optical band gap may find its application as optical interfacing and CIGS solar cells. Moreover, a thin layer of Au ∼20 nm was deposited by the thermal evaporation method on the prepared ZnS films and the optical transmittance spectra show that the bilayers possess a good transmittance ratio while the disappearance of spectral interference was observed as a result of Au deposition.

Investigation of the effect of Sn doping on Al/Sn: ZnS/p-Si diode parameters with C–V and G/ω-V characteristics

In this study, Sn (tin) doped ZnS (zinc sulphide) films have been deposited on the p-type Si (silicon) crystal substrates by the sol-gel dipping technique. The effect of Sn doping in ZnS on diode parameters has been studied via capacitance-voltage (C–V) and conductance-voltage (G/ω-V) measurements in the frequency range of 10 kHz - 1.5 MHz at room temperature. Fermi energy level (EF), carrier concentration (NA), the density of interface states (Nss), barrier heights (ΦB), and built-in potential (Vbi) of the diodes have been obtained by C–V characteristics. Series resistance (Rs) values of diodes have been determined for different frequencies via C–V and G/ω-V measurements.